X-ray technology is widely used for medical, industrial and security imagining purposes. The designs of current c-arm x-ray machines for medical purposes with conventional x-ray imaging exposures a three-dimensional object to form a two-dimensional image. As a result, the 3D spatial resolution in the projection direction is lost. This limitation can be overcome by using c-arm systems and moving the c-arm into different positions to obtain images of the object of interest from different points of view with the so called multi-planar mapping.
Particularly the cardiovascular surgery poses high demanding requirements on the x-ray systems. Additional information of different projections is very important during planning and execution of cardiovascular surgery or catheter manipulation. In prior art this could be achieved by volume imaging methods utilizing a c-arm.
In detail, for the purpose of volume imaging with a current c-arm device, the source and the detector of the c-arm rotates more than 180 degrees on a circular trajectory around the object of interest, e.g. a patient, or to obtain 3D spatial depth information. Several successive mapping images of the object are obtained to achieve the data for constructing of a full three dimensional dataset of the scanned volume. The c-arm carries the radiation source and the detector, both of which are of physically heavy weight in current embodiments. During the rotation of the c-arm on a semi circular trajectory the weight force on both of the devices act perpendicular, whereby the burden on the c-arm throughout the acting of weight forces changes with the rotation of the c-arm, and whereby this results in mechanical deformation of the c-arm construction. For example, if the rotation of the c-arm starting at a horizontal position and the c-arm is turning over 180 degrees into reverse horizontal position, the weight forces acting at the ends of the c-arm cause the maximal mechanical deflection of the c-arm, due to the weight of the detector and the x-ray tube. In consequence the deformation induces a rotation-dependent variation of the alignment of the detector and the radiation source, though that the detector and the radiation source are not arranged opposite to each other. This drawback of the current c-arm construction accounts to the forming of artifacts in multi-planar mapping of the data of the object of interest.
The US Patent Application Number 2004/066907 A1 discloses a medical x-ray diagnostic installation that has a first x-ray radiator attached to a c-arm as well as a second x-ray radiator that is mounted separately from the c-arm at a holder device that can be attached to a stationary structure. A radiation receiver that optionally detects the x-rays emitted by the first x-ray radiator or the x-rays emitted by the second x-ray radiator is attached to the c-arm. The radiation receiver can preferably be rotated around an axis that resides perpendicularly on the plane defined by the c-arm. With this x-ray diagnostic installation, standard examinations for conventional c-arm devices can be implemented and computer tomographic exposures can be generated upon employment of the second X-radiator.
The PCT Application WO2006/090323 discloses a computer tomography apparatus for examination of an object of interest, the computer tomography apparatus comprising a first electromagnetic radiation source adapted to emit electromagnetic radiation to an object of interest, a second electromagnetic radiation source adapted to emit electromagnetic radiation to the object of interest, at least one detecting device adapted to detect electromagnetic radiation generated by the first electromagnetic radiation source and by the second electromagnetic radiation source and scattered on the object of interest, and a determination unit adapted to determine structural information concerning the object of interest based on an analysis of detecting signals received from the at least one detecting device.